Electric contact breaker



Dec. 29, 1931. I A. P. YOUNG ET AL 13839975 ELECTRIC CONTACT BREAKER Filed on. 24, 1929 entors; Arthur P Young, Leonavd GriFFiths,

Th eir Att Patented Dec. 29, 1931 UNITED STATES PATENT OFFICE aamarmmaosm YOUNG, or xmrrnwon'rn, aim LEONARD omrrrn's, or oovmwmy, ENGLAND, assronoas 'ro omwmr. mncrmc comm, A coaromrron or NEW YORK ELECTRIC CONTACT IB BEAKEB Application filed October 24, 1988, Serial No. 402,172, and in Great Britain November 10, 1928.

This invention relates to contact breakers such as are used in connection wlth magneto electric machines or ignition coil apparatus for internal combustion engines.

The object of the present invention is to provide an improved contact breaker of the type which is operated magnetically instead of mechanically as is more usual.

The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of our invention, ref- V erence may be had to the following description taken in connection with the accompanying drawings, in which Fig. 1 is an end elevation of contact breaker embodying our invention, Fig. 2 is a longitudinal section on line AB of Fig. 1, and Fig. 3 is a plan view on the line C-D of Fig. 1.

Referring to the drawings, a ring-shaped permanent magnet 1, having diametrically opposite poles is secured to the contact breaker base 2. This magnet may be cast, forged or built up of laminations. Fastened to the driving member or spindle 3 is a soft iron cylindrical member 4 having diametrically disposed radial polar projections 5, which cooperates as an inductor with the permanent magnet. The number of polar projections 5 is such as to give the required number of breaks per revolution. In the drawings, four are illustrated.

At the poles of the permanent magnet are two pole pieces 6 and 7 which cooperate with the polar projections of the cylindrical member, the pole piece 6 being secured to the magnet. The other pole piece 7 is secured to the a base 2 and has a part 7 parallel to the face 40 of the magnet and a short distance from it to form an air gap. One or both of the ole pieces 6 and 7 may be made of soft iron. he adjustably fixed contact 8 is held by an insulated metal bracket 9 secured to the base 2 and the cooperating contact 10 is fastened to one end of a leaf spring 11 of suitable metal, such as steel or phosphorous bronze, the other end of which is secured to the base 2 at 12. 13 is a soft iron plunger which is fastened to the contact strip or leaf spring 11 and is arranged so as to reciprocate in a hole in the portion of the pole iece 7. The movable contact 1s normally he (1 in en agement with the fixed contactby the aid 0 spring 14, but when the radial polar extensions of the cylindrical inductor member are in proximity to the oles of the permanent magnet, the magnetic field between the pole piece 7 and the plunger 13, and between the plunger and the face of the magnet is greatly intensified,

with the result that the magnetic pull on the plunger overcomes the spring restraining force and separates the contacts.

With the construction above described, relatively small air gaps may be employed thereby giving a maximum flux density and the magnet can be made to such roportions that a large and satisfactory wor ing flux is provided.

In the operation of the contact breaker which we have described rotation of the shaft 3 periodically brings the diametrically opposite projections 5 of the inductor member 1in alignment with the pole pieces 6 and '7, as shown in Fig. 1 of the drawings, so that the flux produced by the annular magnet 1 traverses the pole pieces 6 and 7, the inductor member 4 and acts on the lunger 13 so as to flex the leaf spring 11 and separate the con- .tacts 8 and 10. As soon as the projections 5 of the inductor member 4 move from their position in alignment with the pole pieces 6 and 7, the reluctance of the flux path between the pole pieces 6 and 7 is increased to such an extent that the spring 14 acts on the movable contact-lO carried by the leaf spring 11 so as to bring it into engagement with the stationary contact 8. It will thus be seen that the contacts 8 and 10 are opened and closed four times upon each revolution of the shaft 3.

By duplicating the pole pieces and contacts, it is possible to produce simultaneous breaks on two pairs of contacts. It will be obvious that the details of construction may be varied. For example, another form of contact spring assembly may be' used, and instead of a circular magnet, two semi-circular or other suitably shaped magnets may be employed.

\Vhat we claim as new and desire to secure by Letters Patent of the United States, is:

l. A contact breaker of the type used in electric spark ignition comprising a driving member, an inductor provided with radial polar projections mounted on said driving member, a magnet surrounding said inductor and. having a gap removed from the pole tips thereof, a fixed contact, a movable con tact, and means including a magnetic plunger in the air gap of said magnet for moving said movable contact into and out of engagement with said fixed contact.

2. A contact breaker of the type used in electric spark ignition comprising a base, an annular magnet mounted thereon having diametrically opposite polar projections, one of said polar projections being spaced from said annular magnet to form an air gap, a driving member, an inductor provided with radial polar projections mounted on said driving member, a fixed contact, a spring controlled contact normally in engagement with said fixed contact, and means including a plunger in the air gap between said polar projcction and said magnet for moving said spring controlled contact out of engagement with said fixed contact by the magnetic pull when the polar projections of the inductor are in proximity to the poles of the magnet.

3. A contact breaker of the type used in electric spark ignition comprising a base, an annular magnet mounted thereon, said magnet having diametrica ly opposite poles, one of said poles being spaced from said annular magnet to form an air .1111), a driving member, an inductor provided with radial polar projections mounted on said driving member, a fixed contact, a flat spring extending transversely of the axis of said driven member and fixed at one end to said base, a contact carried by said spring and normally in engagement with said fixed contact, and means including a plunger in the air gap between said polar projection and said annular magnet for moving the contact carried by said spring out of engagement with said fixed contact by the magnetic pull when the polar projections of the inductor are in proximity to the poles of said magnet.

4. A contact breaker of the type used in electric spark ignition, comprising a contact breaker base, a spindle, a magnet secured to the contact breaker base, an inductor with radial polar projections cooperating with the magnet poles secured to the spindle, an iron member secured to the base and having a por tion close to the polar projections of the inductor, a second iron member having a portion parallel to and close to a pole of the magnet, a spring controlled contact-operating soft iron plunger adapted to reciprocate in a hole in the parallel portion of the aforesaid member, the arrangement being such that the spring controlling force is overcome by the magnetic pull on the plunger when the polar projections of the inductor are in proximity to the poles of the magnet.

5. A contact breaker of the type used in electric spark ignition, comprising a contact breaker base, a spindle, a magnet secured to the contact breaker base, said magnet having diametrically opposite poles, an inductor with radial polar projections cooperating with the magnet poles secured to the spindle, an iron member secured to the base and having a portion close to the polar projections of the inductor, a second iron member having a portion parallel to and close to a pole of the magnet, a spring controlled contact operating soft iron plunger adapted to reciprocate in a hole in the parallel portion of the aforesaid member, said first mentioned iron member being attached to the pole of said magnet opposite said plunger, the arrangement being such that the spring controlling force is overcome by the magnetic pull on the plunger when the polar projections of the inductor are in proximity to the poles of the magnet.

6. A contact breaker of the type used in electric spark ignition, comprising a contact breaker base, a spindle, a magnet secured to the contact breaker base, an inductor with radial polar projections cooperating with the magnet poles secured to the spindle, an iron member secured to the base and having a portion close to the polar projections of the inductor, a second iron'member having a portion parallel to and close to a pole of the magnet, a fixed contact, a movable contact, an iron plunger adapted to reciprocate in a hole in the parallel portion of the iron member, a spring normally maintaining the movable contact in engagement with the fixed contact, said contacts being adapted to be separated when the polar projections of the inductor are in proximity to the poles of the magnet.

7. A contact breaker of the type used in electric spark ignition, comprising a contact breaker base, a spindle, a magnet secured to the contact breaker base, an inductor with radial polar projections cooperating with the magnet poles secured to the spindle, an iron member secured to the base and having a portion close to the polar projections of the inductor, a second iron member having a portion parallel to and close to a pole of the magnet, a fixed contact, a flexible strip, a contact mounted thereon, an iron plunger mounted on said strip and adapted to reciprocate in a hole in the parallel portion of the iron member, said contacts being normally in engagement and the plunger held away from the magnet, said contacts being adapted to be separated when the polar projections are in proximity to the poles of the magnet.

8. A contact breaker of the type used in electric spark ignition, comprising a contact breaker base, a spindle, a magnet secured to the contact brea er base, an inductor with radial polar projections cooperating with the magnet poles secured to the spindle, an iron I member secured to the base and having a portion close to the polar projections of the inductor, a second iron member having a portion parallel to and close to a pole of the magnet, a fixed contact, a flexible strip, a contact mounted thereon, an iron plunger mounted on said strip and adapted to reaprocate in a hole in the parallel portion of the iron member, a springnormally maintaining the movable contact in engagement with the fixed contact and the plunger away from the magnet, said contacts being adapted to be separated when the polar pro'ections of the inductor are in proximity to t e poles of the magnet.

9. A contact breaker of the type used in electric spark ignition, comprising a contact breaker base, a spindle, a magnet secured to the contact breaker base, said magnet being substantially ring shaped and in a plane perpendicular to said spindle, an inductor with radial polar projections cooperating with the magnet poles secured to the spindle, said inductor being substantially cylindrical and in a plane parallel to said magnet, an iron member secured to the base and having a portion close to the polar projections of the inductor, a second iron member having a portion parallel to and close to a pole of the magnet, a spring controlled contact operating soft iron plunger adapted to reciprocate in a hole in the parallel portion of the aforesaid member, the arrangement being such that the spring controlling force is overcome by the magnetic pull on the plunger when the olar projections of the inductor are in proximity to the poles of the magnet.

In witness whereof. we have hereto set our hands this 4th day of October, 1929.

ARTHUR PRIMROSE YOUNG. LEONARD GRIFFITHS. 

